Products such as semiconductors or liquid crystal displays are manufactured by performing a series of steps that include cleaning a semiconductor substrate, applying a photoresist, exposure, development, etching, forming an inter-layer dielectric, heat treatment, and dicing. Among such steps, for example, heat treatment may be performed after a pattern is exposed; a Spin On Glass (SOG) material, which is the material of the inter-layer dielectric, is applied; or a photoresist is applied. Heat treatment is an important step necessary for the manufacturing process of a semiconductor or a liquid crystal display.
Heat treatment of a substrate is performed in a heat treatment unit. In this case, it is important to manage the temperature in the heat treatment unit due to a defect of the film thickness of a photoresist or a development failure occurring when the temperature is not appropriately managed. Further, during development, etching, sputtering, Chemical Vapor Deposition (CVD), or the like, controlling the surface temperature of the substrate is required. Therefore, technology has been used to measure the actual temperature of the substrate processed in the heat treatment unit, not the temperature of the heat treatment unit, by using a dummy substrate with a temperature sensor buried therein.
However, in the measurement technology, the temperature sensor that is formed of a material having heat physical properties that differ from those of a substrate, such as heat conductivity or specific heat, is buried in the dummy substrate. For this reason, an error sometimes occurs between the actual temperature of the substrate and the temperature measured by the dummy substrate. Accordingly, a temperature measurement substrate is being developed to more accurately measure the actual temperature of the substrate.
For example, a first patent document discloses a temperature measurement substrate that includes: a substrate where a plurality of concave portions is formed at a surface of the substrate; and a plurality of temperature detection elements which are adhered to the plurality of concave portions and have a crystal vibrator. Further, a second patent document discloses a device for measuring parameters (including temperature) of a substrate. In the substrate temperature measuring apparatus disclosed in the second patent document, a filling material (bonding material or potting material) having specific heat characteristics is used when disposing an electronic processing component and the like (integrated circuit, etc.) in a cavity of the substrate. Therefore, the device can detect a change in the temperature of the substrate substantially identically to a substrate having no electronic processing component.